Propane smell coming from Alde?

sqrpeg

Hoping for some insights on a propane-related issue that has us stumped...

Background details: 2018 320S Boondock (build date 10/2017), Alde 3010 with nuCamp-supplied high altitude kit (2nd regulator) installed.

Last week we were midway through a 4-night boondock in Estes Park, CO when the Alde shut down with the “Gas Failure” error message on the display. Sure enough, the fridge (also running on propane) was out as well, and we noticed a propane smell in the rear driver-side corner above the Alde compartment (but no alarm from the LP/CO detector). I turned off the Alde and fridge, closed the valve at the tank, and we went propane-less for the remainder of the trip.

Our campsite was rife with ground squirrels and chipmunks, so my first assumption was that a varmint got into the underbelly area (easy to do via the inspection holes in the frame behind each wheel) and chewed on a propane hose enough to cause a leak and empty our tank. I figured this would explain the propane smell as well.

Upon returning home I dropped the rear underbelly liner to inspect the hoses back there and couldn’t find any damage. I then hooked up a non-empty LP tank and soapy-bubble-tested the hoses, fittings and high altitude regulator located in that rear underbelly area, but couldn’t find any leaks. I also bubble-tested the portion of the hose coming into the Alde compartment and the fitting to the Alde itself – again no leaks. Just in case, I also confirmed that both ends of the Alde exhaust tube were securely attached.

So, no obvious leaks that I could find. But after airing out the trailer and with the new tank connected, we once again noticed a propane smell in that same corner compartment which “seems” to be emanating from the Alde unit itself.

Weirder still, I can close the LP valve, or even disconnect the tank entirely, and after a while there’s once again a noticeable propane smell in the Alde compartment.

I remember reading somewhere that the Alde might emit a propane smell when the LP tank approaches empty and the pressure drops, or when a refilled tank is initially connected. Can anyone confirm this? Are we just smelling this residual gas and being too hyper-aware now?

Additional thoughts/background/questions:

Based on our LP refill log, I initially thought we had plenty of propane in the tank for last week’s trip. However I did not actually weigh the tank before launching, and I’m now thinking that we did in fact simply run out of gas.

I installed the high-altitude kit for the 3010 back in April of 2018, and since then we’ve been out 70+ nights without problems.

I’m still having trouble dismissing the heavy varmint presence as a red herring (I hate coincidences like that). I’ve only inspected/tested the hoses and fittings towards the rear of the trailer and up front by the tank and main regulator. But if there’s a leak at the 3-way junction or the hoses in the forward underbelly area (or anywhere down there really), why would the smell seem to originate in the Alde compartment above in the cabin? Propane is heavier than air…

If I can find an RV shop that’s not booked into August, my next step is to have the system pressure/leak tested. But in the meantime has anyone else experienced this? Any ideas about what might be going on?

VictoriaP

“I’m still having trouble dismissing the heavy varmint presence as a red herring”

Well. While it’s a long shot, it may be an issue in a different way than you think. Twice now in my personal experience—once in an RV and once at home—a seeming gas leak has turned out to be a deceased and decomposing rodent in a nearby space. Disgusting to deal with, but certainly a cheap and quick fix compared to triaging gas lines.

Assuming it’s an actual leak, perhaps something like this handheld leak detector could help confirm the location? https://smile.amazon.com/Techamor-Y201-Portable-Combustible-Detector/dp/B07BM1XWB8/

Denny16

Actually, I had a similar experience with a cabin, that has propane heat.  The gas stove is a sealed unit, but when the tank rna below 10/percent, a strong “gas smell” was noticeable in the cabin.  Called the propane service, they had to do a low pressure gas leak test, as the tank ran below the minimum level, all was well.  The smell came from the concentration of sulphuric sulfite used in the propane (which normally has no smell) was being released into the pilot and does not burn completely, allowing the smell into the area.

You can have the trailer gas system tested by a RV repair service, and they can do the same test.  Probably what your are smelling with the new tank, is the residual concentration of Sulphur gas left in the lines from the near empty tank.
It is a good idea, not to let your tanks run down past 20 percent, to avoid this issue.
cheers

Bayliss

@sqrpeg, this discussion thread may be of interest to you as far as covering the frame openings:

https://tab-rv.vanillacommunity.com/discussion/8095/are-mice-an-issue/p1

sqrpeg

Thanks all for the feedback!

@VictoriaP - We too were thinking (hoping seems too strong/weird a word in this case ) that it might be a dead mouse instead, but after emptying the entire trailer and checking every nook and cranny, nothing so far.

@Denny16 - That's an encouraging explanation. If it's really only unburned odorant that we're smelling, it could also explain why the LP/CO alarm never triggered. And if low(er) pressure is a factor, those of us with the 3010 high-altitude workaround installed (uses a second regulator) might be especially susceptible(?)

@Bayliss - Thanks for the pointer, covering those holes is next on my list.

pthomas745

I'll add one more:  the worse smell in my trailer was the couple of days after I had completely drained my tanks, and did not add water to the gray tanks afterward.  After a day across the deserts it smelled pretty bad in the trailer.  Are your tanks empty?

sqrpeg

@pthomas745 - Yeah, we learned that lesson last year. We use a grey tank treatment now, and keep some in the traps when the tank is empty.